From 8ce4a8d6ababf340fa91d048208f52d51e21f612 Mon Sep 17 00:00:00 2001
From: Justin Starry <justin@solana.com>
Date: Sun, 25 Apr 2021 22:05:00 +0800
Subject: [PATCH] Annotate clock constants with computed values for quick
 refeerence (#16812)

---
 Cargo.lock               |  1 +
 sdk/program/Cargo.toml   |  1 +
 sdk/program/src/clock.rs | 21 ++++++++++++++++++++-
 3 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/Cargo.lock b/Cargo.lock
index b750f340a..74338df22 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4932,6 +4932,7 @@ dependencies = [
  "solana-frozen-abi-macro 1.7.0",
  "solana-logger 1.7.0",
  "solana-sdk-macro 1.7.0",
+ "static_assertions",
  "thiserror",
 ]
 
diff --git a/sdk/program/Cargo.toml b/sdk/program/Cargo.toml
index c246a0761..e95fa5f10 100644
--- a/sdk/program/Cargo.toml
+++ b/sdk/program/Cargo.toml
@@ -38,6 +38,7 @@ rand = "0.7.0"
 solana-logger = { path = "../../logger", version = "=1.7.0" }
 
 [dev-dependencies]
+static_assertions = "1.1.0"
 assert_matches = "1.3.0"
 bincode = "1.3.1"
 serde_json = "1.0.56"
diff --git a/sdk/program/src/clock.rs b/sdk/program/src/clock.rs
index f923fe550..51f45fc23 100644
--- a/sdk/program/src/clock.rs
+++ b/sdk/program/src/clock.rs
@@ -4,8 +4,12 @@
 // rate at any given time should be expected to drift
 pub const DEFAULT_TICKS_PER_SECOND: u64 = 160;
 
+#[cfg(test)]
+static_assertions::const_assert_eq!(MS_PER_TICK, 6);
 pub const MS_PER_TICK: u64 = 1000 / DEFAULT_TICKS_PER_SECOND;
 
+#[cfg(test)]
+static_assertions::const_assert_eq!(SLOT_MS, 400);
 pub const SLOT_MS: u64 = (DEFAULT_TICKS_PER_SLOT * 1000) / DEFAULT_TICKS_PER_SECOND;
 
 // At 160 ticks/s, 64 ticks per slot implies that leader rotation and voting will happen
@@ -15,22 +19,33 @@ pub const DEFAULT_TICKS_PER_SLOT: u64 = 64;
 // GCP n1-standard hardware and also a xeon e5-2520 v4 are about this rate of hashes/s
 pub const DEFAULT_HASHES_PER_SECOND: u64 = 2_000_000;
 
+#[cfg(test)]
+static_assertions::const_assert_eq!(DEFAULT_HASHES_PER_TICK, 12_500);
 pub const DEFAULT_HASHES_PER_TICK: u64 = DEFAULT_HASHES_PER_SECOND / DEFAULT_TICKS_PER_SECOND;
 
 // 1 Dev Epoch = 400 ms * 8192 ~= 55 minutes
 pub const DEFAULT_DEV_SLOTS_PER_EPOCH: u64 = 8192;
 
+#[cfg(test)]
+static_assertions::const_assert_eq!(SECONDS_PER_DAY, 86_400);
 pub const SECONDS_PER_DAY: u64 = 24 * 60 * 60;
+
+#[cfg(test)]
+static_assertions::const_assert_eq!(TICKS_PER_DAY, 13_824_000);
 pub const TICKS_PER_DAY: u64 = DEFAULT_TICKS_PER_SECOND * SECONDS_PER_DAY;
 
+#[cfg(test)]
+static_assertions::const_assert_eq!(DEFAULT_SLOTS_PER_EPOCH, 432_000);
 // 1 Epoch ~= 2 days
 pub const DEFAULT_SLOTS_PER_EPOCH: u64 = 2 * TICKS_PER_DAY / DEFAULT_TICKS_PER_SLOT;
 
 // leader schedule is governed by this
 pub const NUM_CONSECUTIVE_LEADER_SLOTS: u64 = 4;
 
-pub const DEFAULT_S_PER_SLOT: f64 = DEFAULT_TICKS_PER_SLOT as f64 / DEFAULT_TICKS_PER_SECOND as f64;
+#[cfg(test)]
+static_assertions::const_assert_eq!(DEFAULT_MS_PER_SLOT, 400);
 pub const DEFAULT_MS_PER_SLOT: u64 = 1_000 * DEFAULT_TICKS_PER_SLOT / DEFAULT_TICKS_PER_SECOND;
+pub const DEFAULT_S_PER_SLOT: f64 = DEFAULT_TICKS_PER_SLOT as f64 / DEFAULT_TICKS_PER_SECOND as f64;
 
 /// The time window of recent block hash values that the bank will track the signatures
 /// of over. Once the bank discards a block hash, it will reject any transactions that use
@@ -40,10 +55,14 @@ pub const DEFAULT_MS_PER_SLOT: u64 = 1_000 * DEFAULT_TICKS_PER_SLOT / DEFAULT_TI
 /// not be processed by the network.
 pub const MAX_HASH_AGE_IN_SECONDS: usize = 120;
 
+#[cfg(test)]
+static_assertions::const_assert_eq!(MAX_RECENT_BLOCKHASHES, 300);
 // Number of maximum recent blockhashes (one blockhash per slot)
 pub const MAX_RECENT_BLOCKHASHES: usize =
     MAX_HASH_AGE_IN_SECONDS * DEFAULT_TICKS_PER_SECOND as usize / DEFAULT_TICKS_PER_SLOT as usize;
 
+#[cfg(test)]
+static_assertions::const_assert_eq!(MAX_PROCESSING_AGE, 150);
 // The maximum age of a blockhash that will be accepted by the leader
 pub const MAX_PROCESSING_AGE: usize = MAX_RECENT_BLOCKHASHES / 2;